Type B submarine
The Cruiser submarine Type-B was a class of submarine in the Imperial Japanese Navy which served during World War II. The Type-B submarines were similar to the Type-A apart from not having the headquarters installation; the Type-B submarines were divided into four classes: Type-B Type-B Mod.1 Type-B Mod.2 V22A Type. The 5115th vessel-class submarines remained a design only. Project number S37. Twenty boats were built between 1944 under the Maru 3 Programme and Maru 4 Programme. Project number S37B. Six boats were planned under the Maru Kyū Programme, all boats were completed. On the outside this class looked the same as the I-15 class. Project number S37C. Twenty-one boats were planned under Kai-Maru 5 Programme. Eighteen boats were cancelled in late 1943, because the IJN was setting the Type E submarine as 1945's main submarines. Boats in class Project number S49A. Eighteen boats were planned under the Kai-Maru 5 Programme. However, all boats were cancelled in late 1943, because the IJN concentrated on production of Type-E submarine from 1945 onwards Boats in class "Rekishi Gunzō".
History of Pacific War Vol.17 I-Gō Submarines, January 1998, ISBN 4-05-601767-0 Rekishi Gunzō, History of Pacific War Vol.35 Kō-hyōteki and Kōryū, April 2002, ISBN 4-05-602741-2 Rekishi Gunzō, History of Pacific War Vol.36 Kairyū and Kaiten, May 2002, ISBN 4-05-602693-9 Rekishi Gunzō, History of Pacific War Extra, "Perfect guide, The submarines of the Imperial Japanese Forces", March 2005, ISBN 4-05-603890-2 Model Art Extra No.537, Drawings of Imperial Japanese Naval Vessels Part-3, Model Art Co. Ltd. May 1999, Book code 08734-5 The Maru Special, Japanese Naval Vessels No.31 Japanese Submarines I, Ushio Shobō, September 1979, Book code 68343-31
Kaichū type submarine
The Kaichū type submarine submarines were double-hulled medium-sized submarines of the Imperial Japanese Navy during World War II. They were derived from the Kaigun-shiki Chū-gata Sensuikan. Several variants existed. From 1934 to 1944, the K6 type and the K7 type were built, they were equipped with a 76.2 mm L/40 gun and four 53 cm torpedo tubes for ten type 95 Long Lance torpedoes. Most of these submarines were destroyed in combat, suffering from Allied anti-submarine warfare measures, only the Ro-50 survived the war; the Kaichū type submarines were divided into seven classes: Kaichū I Kaichū II Kaichū III Kaichū IV Toku-Chū/Kaichū V Kaichū VI Sen-Chū/Kaichū VII Project number S7. In 1910s, the Imperial Japanese Navy bought a license of Schneider-Laubeuf design submarine; the IJN used the design as model and built the S Type submarine, the Ha-9 and Ha-10. The Kaichū I is the submarine. Boats in class Project number S18; the Kaichū II had an increased range compared with the Kaichū I, the turning torpedo tubes were removed.
Boats in class Project number S18. Their project number was the same as in the Kaichū II type submarine, however their performance was improved. Boats in class Project number S18A. Improved model from the Kaichū III type. Boats in class Project number S18B, they were built for economic-warfare role. The IJN official designation of these boats was Special Purpose-Medium Type submarine. Boats in class Project number S30, they were planned as a prototype for a mass production submarines in the wartime under the Maru 1 Programme. Boats in class Project number S44; the final design in the Kaichū series. They were equipped with a Freon air-conditioner, because the IJN took into consideration that they were to be active on the equator area too; the official IJN designation of these boats was Medium Type submarine called for short, Medium Type or Submarine-Medium Type. The IJN planned to build these boats under the following Naval Armaments Supplement Programmes: 9 boats in the Maru Rin Programme 12 boats in the Maru Kyū Programme 15 boats in the Maru Tui Programme 43 boats in the Kai-Maru 5 Programme However some of the boats were cancelled and their naval budgets and staffs were transferred to the I-201 class submarines.
Boats in class "Rekishi Gunzō". History of Pacific War Vol.17 I-Gō Submarines, January 1998, ISBN 4-05-601767-0 Rekishi Gunzō, History of Pacific War Extra, "Perfect guide, The submarines of the Imperial Japanese Forces", March 2005, ISBN 4-05-603890-2 The Maru Special, Japanese Naval Vessels No.43 Japanese Submarines III, Ushio Shobō, September 1980, Book code 68343-44 The Maru Special, Japanese Naval Vessels No.132 Japanese Submarines I "Revised edition", Ushio Shobō, February 1988, Book code 68344-36 The Maru Special, Japanese Naval Vessels No.133 Japanese Submarines II "Revised edition", Ushio Shobō, March 1988, Book code 68344-37 The Maru Special, Japanese Naval Vessels No.135 Japanese Submarines IV, Ushio Shobō, May 1988, Book code 68344-39
Japanese cruiser Ibuki (1943)
The Japanese cruiser Ibuki was a heavy cruiser built for the Imperial Japanese Navy during World War II. The lead ship of her class of two ships, she was ordered to be converted into a light aircraft carrier in 1943 before completion to help replace the aircraft carriers sunk during the Battle of Midway in mid-1942; the conversion was delayed and stopped in March 1945 in order to concentrate on building small submarines. Ibuki was scrapped in the Sasebo Naval Arsenal beginning in 1946; the Ibuki-class cruisers were ordered in the Rapid Naval Armaments Supplement Programme of November 1941, they were improved versions of the preceding Mogami class after those ships had been upgraded during the late 1930s. After the heavy losses suffered in the Battle of Midway in early June 1942, the IJN reorganized its current building programs to emphasize aircraft carrier construction. Ibuki, which had only been laid down a few months earlier, had all work suspended while the IJN decided what to do with her.
The navy ordered the shipyard to resume and accelerate construction the following month in order to launch her hull as soon as possible to free her slipway for new carriers. After she was launched in May 1943, construction was suspended again in July while the IJN decided what to do with her; the navy considered completing Ibuki as a high-speed replenishment oiler, but decided to convert her into a light aircraft carrier on 25 August. As designed the Ibukis had a length of 200.6 meters overall, a beam of 20.2 meters and a draft of 6.04 meters. They displaced 12,220 metric tons at 14,828 metric tons at; the Ibuki class was fitted with four Kampon geared steam turbine sets, each driving one propeller shaft using steam provided by eight Kampon Ro Gō-type three-drum boilers. The turbines were intended to produce a total of 152,000 shaft horsepower to give the ships a speed of 35 knots, they carried enough fuel oil to give them an estimated range of 6,300 nautical miles at 18 knots. The main battery of the Ibuki class was intended to be ten 50-caliber 20 cm 3rd Year Type No. 2 guns mounted in twin turrets, three forward and two aft of the superstructure.
The first two forward turrets were on the same level, but the third turret could superfire over the first two. The secondary armament was to consist of eight 40-caliber 12.7 cm Type 89 anti-aircraft guns in twin mounts. The ships were intended to be equipped with four twin 2.5 cm Type 96 light AA guns abreast the funnel. Two twin 13.2 mm Type 93 machine gun mounts were supposed to be mounted on the bridge with 2,000 rounds per gun. The Ibuki-class ships were intended to be armed with four rotating quadruple 61 cm Type 92 torpedo tube mounts, two on each broadside; the ship carried 24 Type 93 torpedoes referred to in post-war literature as the "Long Lance", 16 in the tubes and eight in reserve. Quick-reloading gear was installed for every mount that allowed the reserve torpedoes to be loaded in three to five minutes in ideal conditions. Early warning would have been provided by a Type 2, Mark 2, Model 1 radar mounted at the top of the foremast. A Type 93 passive hydrophone system was intended be fitted in the bow.
The cruisers were designed to carry three aircraft on a platform between the funnel and the mainmast. These would have consisted of a single three-seat Aichi E13A and a pair of two-seat Yokosuka E14Y floatplanes, they would have been launched by a pair of aircraft catapults, one on each side of the aircraft platform. The ship's waterline armored belt was 100 millimeters thick over the propulsion machinery spaces and 140 millimeters thick on the sides of the magazines; the outer ends of the fore and aft machinery compartments was protected by a 105-millimeter transverse bulkhead. The magazines were protected by fore and aft transverse bulkheads 95–140 millimeters thick; the thickness of the armored deck ranged from 35–60 millimeters and the sides of the conning tower were 100 millimeters thick. The main gun turrets were protected by 25 millimeters of armor and the barbette armor ranged from 25 to 100 millimeters in thickness. Ibuki's two aft turbine sets, the four aft boilers and the two innermost propeller shafts were removed with their propellers.
These changes left her with four boilers producing 72,000 shp. The reduced power meant; the space made available was used for aviation gasoline tanks, additional fuel oil tanks, as well as bomb and torpedo magazines. The ship now could carry enough oil for an estimated range of 7,500 nmi at a speed of 18 knots; as part of the conversion, the existing superstructure was razed, a new hangar deck was built above the existing upper deck and a full-length 205-meter flight deck was added. It had a maximum width of 23 meters, two 13-by-11.6-meter aircraft elevators that serviced the single hangar and a small starboard island structure. The ship was bulged to improve her stability. Ibuki's trials displacement increased to 14,800 metric tons and the additional weight increased her draft to 6.31 meters. The ship was to have a light armament of only 22 triple 2.5-centimeter gun mounts, controlled by eight Type 95 fire-control directors, but this was modified in 1944 to sub
Japanese aircraft carrier Unryū
The Japanese aircraft carrier Unryū was the lead ship of her class of fleet aircraft carriers built for the Imperial Japanese Navy during World War II. She was commissioned in mid-1944; the impending American invasion of Luzon caused the IJN to order her to transport aircraft and supplies to the Philippines in December. The ship was torpedoed and sunk by the American submarine USS Redfish in the East China Sea during the voyage; the last purpose-built Japanese carrier construction during World War II was a group of vessels based on an improved Hiryū design, but with individual units differing in detail reflecting the changing circumstances as the conflict in the Pacific approached its conclusion. Unryū was ordered, under the provisional name of #302, as part of the Rapid Naval Armaments Supplement Programme of 1941; the ship was one of 16 Unryū-class aircraft carriers planned, although only three were completed before the end of the war. Unryū had a length of 227.35 meters overall. She had a draft of 8.73 meters.
She displaced 20,450 metric tons. Her crew consisted of men; the ship used the same boilers as used in the heavy cruiser Suzuya. These consisted of four geared steam turbine sets with a total of 152,000 shaft horsepower, each driving one shaft, using steam provided by eight Kampon Type B water-tube boilers; the ship had a designed speed of 34 knots. Unryū carried 3,670 metric tons of fuel oil which gave her a range of 8,000 nautical miles at 18 knots, she had two funnels on the starboard side, each angled below the horizontal. They were fitted with a water-cooling system to reduce the turbulence caused by hot exhaust gases. Unryū's flight deck had a maximum width of 27 meters. A small island was mounted well forward on the starboard side and contained the ship's bridge and air operations control center, it was fitted with a small tripod mast. The ship was designed with two superimposed hangars that were served by two aircraft elevators, each 14 by 14 meters; the elevators had a maximum capacity of 7,000 kilograms and took 19 seconds to go from the lower hangar to the flight deck.
Unryū was fitted with hydraulically operated Type 3 arresting gear with nine cables. She mounted three Type 3 crash barricades. No aircraft catapult; the ship mounted a retractable crane on the starboard side of the flight deck, just aft of the rear elevator. Unryū carried 397,340 liters of aviation gasoline for her aircraft; the ship's air group was intended to consist of 12 Mitsubishi A6M Zero fighters, plus 3 in storage, 27 Aichi D3A Val dive bombers, plus 3 in reserve, 18 Nakajima B5N "Kate" torpedo bombers plus 2 in crates. Amagi's hangars could not accommodate so many aircraft so 11 planes were planned to be permanently carried on the flight deck. In 1943 the air group was revised to consist of 18 Mitsubishi A7M "Sam" fighters, 27 Yokosuka D4Y "Judy" dive bombers and 6 Nakajima C6N "Myrt" reconnaissance aircraft. Of these, the C6Ns were intended to be carried on the flight deck; when the ship commissioned in 1944, neither the A7M nor the C6Ns were yet in service, so the air group was reconfigured to consist of 27 Zeros, 12 D4Ys, 3 of which were to be the reconnaissance version, 9 Nakajima B6N "Jill" torpedo bombers.
By this time, the shortage of carrier-qualified aircrew was such that they were ordered to operate from shore bases and Unryū never embarked her full air group. Unryū's waterline armored belt was 46 millimeters thick over her machinery spaces, but this increased to 140 millimeters over her magazines, her deck armor above the machinery was 25 millimeters thick, but the armor above the magazines was 56 millimeters thick. The ship's primary armament consisted of a dozen 40-caliber 12.7 cm Type 89 anti-aircraft guns in twin mounts on sponsons on the ship's sides. Unryū was equipped with 16 triple 25 mm Type 96 and 3 single Type 96 AA gun mounts, most on sponsons along the sides of the hull; these guns were supplemented by six 28-round AA rocket launchers. Shortly after completion, another 4 triple and 13 single 25 mm mounts were added. For defense against submarines, the carrier was fitted with six depth charge throwers and carried between six and ten depth charges for them. A Type 3 sonar and a Type 93 hydrophone were fitted to detect any submarines.
Two Type 94 high-angle fire-control directors, one on each side of the ship, were fitted to control the Type 89 guns. Each director mounted a 4.5-meter rangefinder. Six Type 95 directors controlled the 25 mm guns and the 12 cm rocket launchers. Early warning was provided by two Type 2, Mark 2, Model 1 air search radars. One of these was mounted on the top of the island while the other retracted into the port side of the flight deck, between the two elevators. In addition, Unryū had two smaller Type 3, Mark 1, Model 3 early-warning radars, one mounted on the tripod mast on the island and the other on the starboard aft retractable radio mast. Unryū was laid down at Yokosuka Naval Arsenal on 1 August 1942 and launched on 25 September 1943. Upon commissioning on 6 August 1944, she was assigned to the 3rd Fleet, she underwent shakedown and trials within Tokyo Bay through mid-September, was transferred to Kure Naval District, from which she made numerous
Hiburi-class escort ship
The Hiburi-class escort ship was a sub class of the Mikura-class escort ships of the Imperial Japanese Navy, serving during and after World War II. In 1943, the Japanese Navy General Staff promoted the building of Escort ship Type-A, the Etorofu class and Escort ship Type-B, the Mikura class. However, the Navy General Staff noted that too many man-hours of work were needed for their building; the Navy Technical Department used the Ukuru's basic designs for the new drawings. It was a chimera of Ukuru classes; the new drawings had the following characteristic. Armaments and under waterline designs were same as Mikura. Everything else was same as in the Ukuru; the Kampon estimated man-hours for building will be between 42,000 to 40,000. The new drawing was sent to Sakurajima Shipyard; the Mikura class and the Ukuru class that had not been started were converted to the Hiburi class. The Hitachi Zōsen build all of the Hiburi class vessels. Classification of the Kaibōkan classes in IJN official documents The Shimushu, Mikura and Ukuru were classed in the Shimushu class.
The IJN changed their classification on 5 June 1944, because the shipyards and commanders were confused. The Escort ship Type-B and Modified Type-B were combined to the Escort ship Type-A, Type-Bs became extinct thereby. Shimushu-class escort ship Etorofu-class escort ship Type C escort ship Type D escort ship Destroyer escort Tacoma-class frigate Flower-class corvette "Rekishi Gunzō". History of Pacific War Vol.51, The truth histories of the Imperial Japanese Vessels Part.2, June 2002, ISBN 4-05-602780-3 Ships of the World special issue Vol.45, Escort Vessels of the Imperial Japanese Navy, "Kaijinsha". February 1996 Model Art Extra No.340, Drawings of Imperial Japanese Naval Vessels Part-1, "Model Art Co. Ltd". October 1989 The Maru Special, Japanese Naval Vessels No.28, Japanese escort ships, "Ushio Shobō". June 1979
Japanese fleet oiler Hayasui
The Hayasui was a Japanese fleet oiler of the Imperial Japanese Navy, serving during World War II. Hayasui was completed as one of the Kazahaya class fleet oilers. After lack of reconnaissance planes was identified as a contributing factor to defeat of the IJN at the Battle of Midway, aviation facilities were added to Hayasui for accompanying the carrier task force; the IJN added the function of food supply ship to Hayasui to improve carrier task force endurance following experience at the Battle of the Santa Cruz Islands. 24 April 1944: Completed. May 1944: Sailed to Tawi-Tawi for Operation A. 19 to 20 June 1944: Participation to the Battle of the Philippine Sea and damaged. 10 August 1944: Repairs were completed for convoy Hi-71 departure from Moji to Singapore. 03:20, 19 August 1944: Hayasui was torpedoed by USS Bluefish at west of Vigan City. About 05:00: Explosion and sunk at 17°34′N 119°24′E. 10 October 1944: Decommissioned. "Rekishi Gunzō". History of Pacific War Vol.62 "Ships of The Imperial Japanese Forces, January 2008, ISBN 978-4-05-605008-0 Ships of the World special issue Vol.47, Auxiliary Vessels of the Imperial Japanese Navy, "Kaijinsha".
Japanese escort ship Matsuwa
Matsuwa was one of fourteen Etorofu-class escort ships built for the Imperial Japanese Navy during World War II. The Etorofu class was an improved version of the preceding Shimushu class with a greater emphasis on anti-submarine warfare; the ships measured 77.72 meters overall, with a draft of 3.05 meters. They displaced 880 metric tons at 1,040 metric tons at deep load; the ships had two diesel engines, each driving one propeller shaft, which were rated at a total of 4,200 brake horsepower for a speed of 19.7 knots. The ships had a range of 8,000 nautical miles at a speed of 16 knots; the main armament of the Etorofu class consisted of three Type 3 120-millimeter guns in single mounts, one superfiring pair aft and one mount forward of the superstructure. They were built with four Type 96 25-millimeter anti-aircraft guns in two twin-gun mounts, but the total was increased to 15 guns by August 1943. 36 depth charges were stowed aboard but this increased by August 1943 to 60 depth charges with a Type 97 81-millimeter trench mortar and six depth charge throwers.
They received Type 22 and Type 13 radars and Type 93 sonar in 1943–44. Matsuwa was launched by Mitsui, Tumano, on 19 April 1942 and completed on 1 April 1943. On 2 August 1944, she was sunk by the submarine USS Harder in Hidai Bay. Chesneau, Roger, ed.. Conway's All the World's Fighting Ships 1922–1946. Greenwich, UK: Conway Maritime Press. ISBN 0-85177-146-7. Jentschura, Hansgeorg. Warships of the Imperial Japanese Navy, 1869–1945. Annapolis, Maryland: United States Naval Institute. ISBN 0-87021-893-X. Matsuwa on combinedfleet.com